Android: Fix texture leak in QAndroidTextureVideoOutput

Simplify the ownership of the OpenGL resources and make it simpler
to release individual resources as needed. Previously we would
reset the texture handle without releasing it back to the system, making
us leak texture each time the video output was reset.

Also, be consistent with the type used for the texture handle.

Task-number: QTBUG-54340
Change-Id: Ic3b3c7322677a909e51aa5983fa99ccf8b290302
Reviewed-by: Yoann Lopes <yoann.lopes@qt.io>